Finish Upgrading Webpacker to v5

Gemfile

@@ -32,7 +32,7 @@ gem 'simple_form', '~> 5.0'
 gem 'sprockets', '< 4'
 gem 'turbolinks'
 gem 'uglifier', '>= 1.3.0'
-gem 'webpacker', '~> 4'
+gem 'webpacker', '~> 5'
 
 group :development, :test do
   gem 'better_errors', '~> 2.4.0'

Gemfile.lock

@@ -330,6 +330,7 @@ GEM
       tilt
     sdoc (1.1.0)
       rdoc (>= 5.0)
+    semantic_range (2.3.0)
     simple_form (5.0.2)
       actionpack (>= 5.0)
       activemodel (>= 5.0)
@@ -366,10 +367,11 @@ GEM
       addressable (>= 2.3.6)
       crack (>= 0.3.2)
       hashdiff
-    webpacker (4.2.2)
-      activesupport (>= 4.2)
+    webpacker (5.2.1)
+      activesupport (>= 5.2)
       rack-proxy (>= 0.6.1)
-      railties (>= 4.2)
+      railties (>= 5.2)
+      semantic_range (>= 2.3.0)
     websocket-driver (0.7.2)
       websocket-extensions (>= 0.1.0)
     websocket-extensions (0.1.5)
@@ -425,7 +427,7 @@ DEPENDENCIES
   tzinfo-data
   uglifier (>= 1.3.0)
   webmock (~> 3.2.1)
-  webpacker (~> 4)
+  webpacker (~> 5)
 
 RUBY VERSION
    ruby 2.5.8p224

babel.config.js

@@ -56,9 +56,7 @@ module.exports = function(api) {
       [
         '@babel/plugin-transform-runtime',
         {
-          helpers: false,
-          regenerator: true,
-          corejs: false
+          helpers: false
         }
       ],
       [

config/webpacker.yml

@@ -6,12 +6,11 @@ default: &default
   public_root_path: public
   public_output_path: packs
   cache_path: tmp/cache/webpacker
-  check_yarn_integrity: false
   webpack_compile_output: true
 
   # Additional paths webpack should lookup modules
   # ['app/assets', 'engine/foo/app/assets']
-  resolved_paths: []
+  additional_paths: []
 
   # Reload manifest.json on all requests so we reload latest compiled packs
   cache_manifest: false
@@ -53,9 +52,6 @@ development:
   <<: *default
   compile: true
 
-  # Verifies that correct packages and versions are installed by inspecting package.json, yarn.lock, and node_modules
-  check_yarn_integrity: true
-
   # Reference: https://webpack.js.org/configuration/dev-server/
   dev_server:
     https: false

package.json

@@ -12,7 +12,7 @@
     "yarn": ">=1.0.2"
   },
   "devDependencies": {
-    "webpack-dev-server": "^3.9.0"
+    "webpack-dev-server": "^3.11.0"
   },
   "engines": {
     "yarn": ">=1.0.2"